Pedestrian walkway between 2 buildings fire separation requirements?

[AArchitect]

I have two buildings (type IIA 64' tall 4 stories and 45' tall 2 stories) that are separated by 75' and connected at one spot by one story fully enclosed pedestrian walkway with an exterior exit in the middle. I really need to avoid having to provide 2-hour separation at the end of each walkway and it seems like I can avoid that since it complies with section 3104.5.2.

However, the plan reviewer is saying that the exterior walls of the two buildings need to be rated because of section 3104.40 for tunneled walkways. This is confusing to me as this is not a tunnel and is on grade and only 12' to the top of the roof of the passageway. Am I missing something here or is the plan reviewer incorrect?

3104.5 Connections of Pedestrian Walkways to Buildings

The connection of a pedestrian walkway to a building shall comply with Section 3104.5.1, 3104.5.2, 3104.5.3 or 3104.5.4.

3104.5.2 Alternative Separation

The wall separating the pedestrian walkway and the building shall comply with Section 3104.5.2.1 or 3104.5.2.2 where:

1. The distance between the connected buildings is more than 10 feet (3048 mm).
2. The pedestrian walkway and connected buildings are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, and the roof of the walkway is not more than 55 feet (16 764 mm) above grade connecting to the fifth, or lower, story above grade plane, of each building.

 

[RLGA]

The IBC defines a pedestrian walkway but does not define a tunnel, which is unfortunate. However, the IBC states that undefined terms shall use their "ordinarily accepted meanings." In every definition I look at, it means underground.

Thus, you do not have a tunnel, and Section 3104.10, which applies only to tunnels, is irrelevant to your situation.

 

[AArchitect]

Thanks for the reply. I talked to the plan reviewer and for some reason he thought it was a tunnel and was fine changing his comment.